Expert A's to Your Beauty Q's: Sunless Tanning

Q: Whenever I use self-tanner, I always have at least one streaky, blotchy spot. What can I do?

San Francisco dermatologist Jennifer Linder, MD, says:

Streaks and spots do happen, but you have a much greater chance today of achieving an even, natural-looking tan compared with decades ago. Then, as now, self-tanners used a colorless sugar called dihydroxyacetone (DHA), which interacts with surface skin cells to produce a tanned appearance within about an hour. Streaks develop because of uneven application or an excess of built-up cells on your skin.

To avoid a "blotched job," exfoliate the areas you're going to tan before applying self-tanner. My preference for face and body is a scrub with particles that are perfectly round so they glide over the skin, removing cell debris without irritation. Try Olay Skin Smoothing Cream Scrub ($6.99) or Kiss My Face So Refined Jojoba & Mint Facial Scrub ($15), a skin polisher with gentle jojoba beads.

After you exfoliate, mix your self-tanning product -- I like Jergens Natural Glow Express Body Moisturizer ($8.99) for a gradual, even tan -- with a little body moisturizer so it spreads evenly. Allow the product to dry completely before topping your skin with another light layer of moisturizer. Try PCA Skin Body Therapy ($44), a cream that provides therapeutic levels of moisture and helps keep skin free of cell debris.

I usually recommend self-tanning at night so you can wake up, shower, and slather on your daily body moisturizer. Most self-tanners don't protect you from UV rays, so a daily sunscreen with SPF of 30 or more is a must.

Chicago dermatologist Carolyn Jacob, MD, says:

In addition to exfoliating your skin to even out the surface, my best advice is to use your hand to really blend the product in. Even distribution is key.

Then moisturize, which keeps the cells that trap the self-tanner solution on the skin longer, making your faux tan last. Incidentally, it's not a good idea to put moisturizer on right before you self-tan because then the formula can't stick to the skin cells. The exception to this is to apply a tiny bit first to knees, elbows, ankles, and feet to help the self-tanner go on evenly.